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2016-09-08 20:32:16 -0500 asked a question Inter VM dependency on two socket hypervisor

Hi All, We are seeing an interesting scenario during the throughput tests.

System Configuration:

  • Two socket having 10 cores each.
  • VM-0 cores are pinned to phy cores 2-to-9 on Socket# 0 and emulator pin pinned on core 1
  • VM-1 cores are pinned to 12-19 on Socket# 1 and emulator pin pinned on core 11
  • Each are 8 core VMs
  • CPU: E5 2687W v3 @ 3.1 Ghz
  • Memory 65 GB on each socket
  • All SR-IOV ports are Intel 40G
  • Centos 7.0 , Kernel 3.10.0-123.9.3.el7.x86_64
  • Using library: libvirt 1.2.18
  • Using API: QEMU 1.2.18
  • Running hypervisor: QEMU 2.4.0

Issue Description :

Issue we are seeing is: somehow a VM-1 running on CPU socket# 1, affects the throughput of VM-0 running on CPU socket# 0, even after making sure all the isolation done in libvirt XML (more detail in the Note 1 at the end)

Issue is VM-0 drops traffic on port connected to traffic generator. We found that VM-0 drops traffic only if, VM-1 is running on socket #1. If we either remove VM-1 or very less load on VM-1, then we don’t see drops.

Note 1:

  • Cores for each of them is pinned on their respective sockets

  • Emulator pins are pinned to respective cpu sockets/core

  • Memory for each is from the respective numa nodes, like for VM-0 running on socket 1, huge pages are from numa node 1

  • SR-IOV interfaces are on the pci slots connected to correct CPUs, like IO interfaces of each one of the VM is using PCI slots which are connected to their CPU socket,

  • Tried with and without hyper-threading

  • Enabled the following BIOS settings:

    Intel VT, SR-IOV support, Energy Efficient

2015-01-21 20:13:22 -0500 received badge  Supporter (source)
2014-12-08 22:22:08 -0500 asked a question How to get Base IO address for config drive file

Hi All, I tried to read configuration file in my real time operating system passed by qemu-kvm. The configuration drive format as ISO 9660. When I tried reading configuration file using ATA/IDE driver with bus id as zero and drive id as one, the recalibration of device has failed. So I tried using SCSI driver with base IO address as 0x330 and IRQ number as 0xB, sensing of device has failed. Please let me know the base IO address and IRQ number passed by qemu-kvm for the ISO 9660 device using the config drive option.

Openstack Version: Havana

[root@localhost cloud-init-ide(keystone_admin)]# nova --version

2.16.0

[root@localhost cloud-init-ide(keystone_admin)]# neutron --version

2.3.4

[root@localhost cloud-init-ide(keystone_admin)]# glance --version

0.12.0

[root@localhost cloud-init-ide]# /usr/libexec/qemu-kvm --version

QEMU PC emulator version 0.12.1 (qemu-kvm-0.12.1.2), Copyright (c) 2003-2008 Fabrice Bellard

Qemu Log: LC_ALL=C PATH=/sbin:/usr/sbin:/bin:/usr/bin /usr/libexec/qemu-kvm -name LTE-CPM -S -M rhel6.5.0 -enable-kvm -m 4051 -realtime mlock=off -smp 4,sockets=4,cores=1,threads=1 -uuid 14b1596f-b616-4a87-b3b2-26d4b2bfe12b -smbios type=1,product=LTE KVM Controller -nographic -nodefconfig -nodefaults -device sga -chardev socket,id=charmonitor,path=/var/lib/libvirt/qemu/LTE-CPM.monitor,server,nowait -mon chardev=charmonitor,id=monitor,mode=control -rtc base=utc,driftfix=slew -no-shutdown -no-acpi -device piix3-usb-uhci,id=usb,bus=pci.0,addr=0x1.0x2 -drive file=/var/lib/libvirt/images/cpmdiskvmxml.qcow2,if=none,id=drive-ide0-0-0,format=qcow2 -device ide-drive,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0,bootindex=1 -drive file=/var/lib/libvirt/images/disk.config,if=none,media=cdrom,id=drive-ide0-1-1,readonly=on,format=raw -device ide-drive,bus=ide.1,unit=1,drive=drive-ide0-1-1,id=ide0-1-1 -netdev tap,fd=32,id=hostnet0,vhost=on,vhostfd=33 -device virtio-net-pci,netdev=hostnet0,id=net0,mac=4a:88:0f:0b:b9:bf,bus=pci.0,addr=0x4 -netdev tap,fd=34,id=hostnet1,vhost=on,vhostfd=38 -device virtio-net-pci,netdev=hostnet1,id=net1,mac=1a:1b:9b:39:e9:38,bus=pci.0,addr=0x5 -chardev pty,id=charserial0 -device isa-serial,chardev=charserial0,id=serial0 -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x6 -msg timestamp=on char device redirected to /dev/pts/3

Regards, Meganathan